This band-pass filters designed by author of TRX "Klopik". Each filter consists of dual coils assembled on 6mm tube. The adjustment is easy and completes by moving the coils towards and backwards to each other. That is quite enough in this simple device.
The band switches automatically via relays.
Block diagram is available on photo.
The KIT is recommended for receivers, Klopik TRX and other simple devices.
*Recommended for novice.
Relays 13.8V (working range is 13.8V..27Volts)